Electric connector assemblies in which a pair of connectors is locked by using a lock mechanism having a rack and a pinion have been introduced in many patent documents. For example, an electric connector assembly 20 described in the specification of German Utility Model No. 8714016 is shown in FIG. 6. The electric connector assembly 20 has the first and the second connectors 21, 22 that are engaged with each other. The second connector 22 has an operation lever 23 having a pinion 23a in its housing. The operation lever 23 is rotatably connected to the housing with a shaft. The first connector 21 has a structure in which a rack 21a is formed in a cavity of its housing.
The connectors 21, 22 are engaged with each other by the following procedures. First, the second connector 22 is inserted into the cavity of the first connector 21, and the rack 21a and the pinion 23a are engaged with each other. When the operation lever 23 is rotated, the second connector 22 is fully engaged with the first connector 21 inside the cavity 21b of the first connector 21. The connectors 21, 22, are released from each other by rotating the operation lever 23 in the opposite direction. The pair of connectors 21, 22 is anchored by engaging the operation lever 23 at a closed position with a latch, namely, making latch engagement at an end of rotation position. With this configuration, the engagement between the connectors can be quickly performed by only inserting into the other connector and making snap engagement between the connectors. Lever-type electric connector assemblies having the same type of operation levers are introduced in U.S. Pat. Nos. 5,833,484 and 6247966B1.
The electric connector assembly described in the specification of U.S. Pat. No. 6,247,966B1 is constructed from a pair of connectors. As shown in FIG. 7, the first connector 25 has a connector body 26 having contacts, and a housing 27 having a cavity 27a and an operation lever 28. The size of the cavity 27a is decided so as to be capable of housing the connector body 26. The connector body 26 is housed in the cavity 27a of the housing 27. When the connector body 26 is inserted in the cavity 27a of the housing 27, a locking projection part 26a formed on a sidewall of the connector body 26 is engaged with a catching part 27b formed in the housing 27 via snap engagement.
With the above-described configurations, engagement of a pair of connector assemblies is properly made and secured with the operation lever, which reduces accidental release of the engagement. For this reason, these connectors are used in airbag systems of vehicles that require special emphasis on safety and reliability.
In these electric connector assemblies, however, a receptacle of a receptacle-type connector may be engaged with another connector in a condition that the receptacle is not properly housed in a cavity of a connector housing when the receptacle is inserted into the housing. If an operation lever is rotated in the condition that the receptacle is not properly housed in the connector housing, contacts mounted to the receptacle are not properly connected with contacts of the other connector. As a result, abnormal stress may be applied to the contacts and the contacts may be damaged. In connector assemblies in which a connector housing and a receptacle are engaged via snap engagement, such as the connector of U.S. Pat. No. 6,247,966B1, whether the receptacle is properly hosed in the connector housing cannot be confirmed. Moreover, this type of connector is expected to have more emphasis on safety and reliability. If the connector housing and the receptacle are not properly engaged, safety level may be reduced.